LED lighting aluminium extrusionsAs the base material of the lamp bead, the LED bracket is an important material of the LED lamp bead and the carrier of the LED chip. The bracket is responsible for the heat dissipation and conduction, the thermal resistance of the lamp bead and the initial defect rate. There are many reasons for SMD disconnection due to design defects and quality defects of LED brackets. According to different applications, there are different types of lamp beads, which are actually different types of LEDs caused by different types of LED brackets.
The specific categories are: in-line bracket, patch bracket, high-power bracket, flat bracket and COB bracket. Since the bracket of the LED needs to be electrically and thermally conductive, metal is used as the base material. At the same time, some areas need to be insulated, which requires the use of engineering plastics. Therefore, the general LED bracket is formed by metal stamping and then injection molding. As light-emitting diodes, LEDs need to be electroplated on the inner surface of the metal, and silver is used as a good light-reflecting material, so generally LEDs are electroplated with silver surface treatment.
The bracket materials used for LEDs with different powers are also different. PPA is generally used for low power, PCT is generally used for medium power, and some high-power LEDs are currently made of EMC materials.
All plastic materials have water absorption, so the bracket needs to be dehumidified by baking during the production process of LED lamp beads. The treatment of the plating layer is the key point of the bracket, and the thickness and quality of the plating layer are related to the luminous flux and welding performance behind.
In fact, the first condition to choose a good LED is to choose a good bracket. At present, there are some products on the market that are formed by stamping, re-plating and injection molding of iron substrates, which are of poor quality.
It is better to use copper material for medium power, and the electroplating layer needs to be controlled at about 80U'', but many manufacturers only require electroplating to 40U''. weld. Most of the high-power brackets now use ceramic substrates. If it is a ceramic material, it is necessary to find out the key points of the composition and coating of the ceramic.
The high-power COB lamp beads that appear on the market are generally formed by electroplating with copper plate and then injection molding. CITIZEN's COB lamp bead bracket is formed by pressing aluminum materials. Of course, the selection of CITIZEN aluminum materials has certain conditions. The PCB material is the BT board material used, and the adhesive in the middle is critical. Therefore, the key to doing well is how to do it and how to choose materials. This is the most important thing.